Generally, an internal combustion engine for an automobile sucks the air needed for driving the engine by using the negative pressure generated when the engine is driven.
In order to increase the output of the engine, the amount of air provided to the engine should be increased. In order to make an automobile more powerful, a supercharger, which is like a turbocharger, is provided in the automobile. The supercharger increases the supply of air to the internal combustion engine of the automobile.
The supercharger supplies more air than the normal amount of air sucked by the engine using negative pressure. With the supercharger, the engine ignites more fuel with the increased amount of air, thus increasing the output of the engine.
The prior supercharger, like the turbocharger that is adopted in many kinds of automobiles, supplies air to the engine by using a turbine, that is operated by the exhaust gas of the engine.
However, the prior supercharger has many components and complicated construction. Therefore, the prior supercharger is expensive in its cost and heavy. The weight of the supercharge disadvantageously increases the weight of the automobile.